A2 - Psychology - The nature of dreams

Freud's psychoanalytic theory - Description

• Freud proposed that dreams express unconscious thoughts.
• Dreams protect us by allowing repressed primary process thinking (unacceptable id urges) to happen and by fulfilling unconscious wishes.
• Dreams are symbolic. The real mean (latent content) is changed into a less threatening form (the manifest content) through dreamwork.
• Processes in dreamwork include condensation (complex thoughts are simplified) and symbolism (a symbol rerplaces an action, person or idea).
• Not all dream content is symbolic: 'sometimes a cigar is just a cigar'.

Freud's psychoanalytic theory - Evaluation

• Freud's theory is difficult to falisfy as Freud claimed interpretations were correct either if the dreamer accepted them or if they rejected.
• Nightmares are unlikely to represent wish fulfilments or protect the sleeper although Freud did suggest that some dreams are not wish fulfuilments, e.g. ones that are 'sensible warnings'.
• According to Freud, dreams should be bizarre but Snyder found that only 5% of dreams are described as 'exotic' and 70% are 'highly coherent'. 

Freud's psychoanalytic theory - Research evidence

• Solms described brain-damaged patients who had no REM activity but still reported dreams and ones with REM activity who reported no dreams.
• Solms used PET scans to show that the rational part of the brain is inactive (e.g. prefrontal cortex) during REM sleep whereas memory and motivation (e.g. the limbic areas) are active. Fit with Freud's idea of inactive, rational ego and active id (linked to limbic area).
• However, same evidence could contradict Freud's theory as the rational part of the mind is needed for dreamwork (Braun).
• Computer simulations of the brain support condensation because neural networks condense 'memories' when overloaded (Hopfield et al).
• Zhang proposed continual-activation theory - memory processing occurs during sleep involving the unconscious which fits with Freud's theory.

Hobson and McCarley's activation-synthesis - Description

Activation

• EEG's show the cerebal cortex is active in REM sleep even though there are few external stimuli and we are paralysed (except for the eye muscles)
• During REM sleep, the brainstem generates random signals like those from external stimuli.

Synthesis

• The prefrontal cortex combines random signals from brainstem with exisiting memories, making into a coherent sequence.
• Although the sequence has no inherent meaning, the dream may have meaning because it contains the dremaer's memories (Hobson).

Revisions

• Hobson (1994) suggested that low levels of noradrenaline and serotonin explain the bizarre nature of dreams and loss of attention.

Hobson and McCarley's activation-synthesis - Evaluation

Supporting evidence

• PET scanning shows that the brainstem is active in REM sleep (Braun et al).
• Solms showed that the prefrontal cortex is inactive during dreaming, could explain bizarre nature of dreams - but doesn't explain synthesis.

Challenging evidence

• Activation-synthesis predicts that dreams, and REM activity are linked but brain damage can affect the two independently (Solms), people can dream during NREM sleep (Antrobus et al), and children dream less than adults though they have REM activity (Foulkes).
• Hobson suggests that REM activity may be present during apparently NREM sleep.
• Snyder's evidence suggests that dreams are coherent.
• Zhang's theory also fits with activation-synthesis hypothesis because drop in levels of brain activity trigger the continual-activation mechanism.